In manufacturing environments, measuring the temperature of an object without contact has proven to be a complex and daunting task. Objects in motion are often difficult to touch (e.g., molten sapphire), and objects that are too hot will damage the temperature sensor. The object of interest also may be easily damaged by contact, thereby precluding measurement of its temperature. Dependable means for gauging high temperatures have evolved over the centuries, from the primitive visual methods used by blacksmiths as they forged steel, to today's highly accurate means of industrial temperature measurement (e.g., optical pyrometry).
It is a well-known phenomenon that hot objects emit light. The hotter, the brighter. In fact, this phenomenon is one of the more important cornerstones of many modern technologies. Among them is radiometric temperature measurement, otherwise known as optical pyrometry.
The essence of the system is that an object of interest, or target, is viewed with some type of optics. The object is imaged on an electronic detector of some type that has been accurately calibrated to produce a known relationship between input (light intensity) and output (temperature reading). The output is typically routed into a control system and used as feedback to adjust the process in real time.
Optical pyrometers often use an amplifier to increase a voltage representing the detected optical signature of the target being measured. These amplifiers introduce various challenges to optical pyrometry that have yet to be adequately addressed. There is therefore a need in the art for an improved amplification stage for an optical pyrometer.